Power control apparatus



n Mavl'Ch 18, -1969 A. w. SCHNEIDER 3,434,040

POWER CONTROL APPARATUS Original Filed Feb. 10, 1964 I N VEN TOR. em/f/f/Jawaff United States Patent O 3,434,040 POWER CONTROL APPARATUS Arthur W. Schneider, New York, N.Y., assignor to Commercial Radio-Sound Corp., New York, N.Y., a corporation of New York Continuation of application Ser. No. 343,701, Feb. 10,

1964. This application Jan. 12, 1967, Ser. No. 608,941

U.S. Cl. 323-74 2 Claims Int. Cl. H05b 41 02 ABSTRACT OF THE DISCLOSURE A control circuit for providing a pre-programmed Voltage schedule to a lamp dimming circuit. The rate at which the illumination increases and decreases and the time duration for which the lamps are lighted between their minimum and maximum illuminations can be independently controlled and repeated by controlling the charge and discharge of capacitors.

This application is a continuation of U.S. patent application Ser. No. 343,701, filed Feb. 10, 1964, now abandoned.

This invention relates to control devices and more particularly it relates to the control of electric load devices of which electric illuminating units are typical.

A principal object of the invention is to provide a novel control arrangement for applying to an electric circuit a controlling voltage which can be selected with any desired maximum or minimum and with any desired rate of rise or fall between any chosen maximum and minimum.

In certain of the arts it is desirable to be able to apply a control voltage of a selected voltage range and with selective continuous increments or decrements in the chosen range. Thus in theater lighting, outdoor display lighting, exhibit lighting and the like, it may ybe required to operate a bank of incandescent lamps or other light sources, so that after turning on a control switch or energizing a control relay the lamps gradually and continuously increase their illuminating effect; and likewise, after turning olf the control switch or de-energizing the control relay, the lamps grad-ually and continuously decrease their illuminating effect. It is also an advantage to be able to control the rate at which the illumination increases and decreases and the time duration for which the lamps are lighted between their minimum and maximum illuminations. Furthermore, it is desirable to be able to control the rise from minimum to maximum independently of the rate of decay from maximum to minimum. These conditions of control are particularly desirable when various banks of colored lights are to be used, and relative brightness, rate of increase and decrease of brightness and the duration are to be independently controlled so as to produce special colored combinational illumination effects.

Heretofore it has been the general practice to employ a resistor, potentiometer or rheostat to control the light intensity. If such elements are manually operated, it has been necessary for an attendant to operate the adjusting element of the potentiometer resistor manually and visually to watch the rate at which the illumination increases or decreases. This, of course, introduces the personal equation, and the artistic or visual etect is dependent upon the attendants judgment. Furthermore, where a number of functions are to be controlled, such as a minimum, maximum, rate of rise during one condition, and rate of decay during another condition, a corresponding number of manual control elements must be continuously manipulated and their relative and combinational effects visually judged.

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Even in those cases where the potentiometers are motor driven, similar problems arise. If each potentiometer is driven by an individual motor, it is not economically feasible to be able to vary the rate at which the motor for each unit is driven unless specially designed motors are employed. In other words, each motor is usually designed to operate at maximum eiciency for a given set of parameters. Furthermore, with motor driven controls, it is expensive to devise a control system where the rate of rise of lamp voltage is different from the rate of fall. These special motors with associated mechanical connections to the various potentiometers must be designed to have one rate of speed for the rise and a different'rate for the fall. If a simple reversible motor is employed it is diicult to make the speed different in one direction of rotation from that of the other. Where motor driven potentiometers are employed, there is always present the possibility of flicker, or irregularity as the potentiometer arm rides over the usually wire-Wound potentiometer resistor.

Accordingly it is another object of this invention to provide a simple electronic device which is capable of varying a voltage to a utilization circuit so that the rate of increase, the rate of decrease, the minimum and the maximum can be independently controlled and repeated with precision and in such a way that the said rates can be made different, using a simple switch manipulation.

Another object is to provide a light controlling system and the like wherein the maximum and minimum illuminations can be pre-selected, and the rate of increase and decrease can also be pre-selected, `and the lamps can be lighted accordingly, without icker or in steps.

Another object is to provide a light controlling system employing relatively simple switches which can be set so that the minimum to maximum illumination and the rate of increase and decrease can be independently chosen and duplicated from time to time, thus rendering the .system readily susceptible to control by a programming device such as a perforated card controller of any known kind.

A feature of the invention relates to a utilization voltage control device which is capable of delivering to a utilization circuit a voltage which can be chosen with a pre-determined minimum, a pre-determined maximum, and with independent control of the rate of rise and fall between maximum and minimum, all of which conditions can be precisely duplicated at any desired time.

A further feature relates to the novel organization, arrangement and relative interconnection of parts which cooperate to provide a simplified and ilexible system for applying a control voltage to a utilization load.

Other features and advantages not specifically enumerated will be apparent after a consideration of the following detailed descriptions, the appended claims and the attached drawing.

While the invention will be described Ias applied to a utilization circuit for controlling a plurality of electric incandescent lamps, it will be understood that such is done merely by way of illustration. Thus in certain other iields, for example, in the X-ray treatment eld, it is highly desirable to be able to control the minimum and maximum intensity of the X-ra-ys as well as their independent control during increase and decrease, and also that each cycle of application of the X-rays be capable of duplication with precision.

Referring to the drawing:

FIG. 1 is a schematic wiring and block diagram of a lamp control system embodying the invention;

FIGS. 2 and 3 are graphs representing typical conditions of the control voltage derived from the control unit of FIG. l.

Referring to FIG. 1 the device 10 represents any known source of regulated power supply which is capable of receiving the commercial alternating current voltage at its input terminals and converting the said alternating current into a direct current of highly stable and precisely regulated amplitude. The device 11 represents any well known utilization circuit, such for example as a lamp dimmer circuit of the Century Type CCR Dimmer, Model 406, made and sold by Century Lighting Inc.

Associated with the output of the dimmer circuit is a bank of incandescent lamps 12 whose illumination, intensity and duration of illumination are to be controlled from the circuit 11. Connected between the device and the device 11 is a unit 13 embodying features of the invention. This unit comprises input terminals 14, 15, and output terminals 16, 17. Connected across the input terminals 14 and 15 is a potentiometer resistor 18 whose adjustable contact arm 19 is mechanically connected, as indicated by the dot-dash line 20, to an adjusting knob 21. Also conneced across the input terminals 14, is another potentiometer resistor 22 whose adjustable contact arm 23 is connected, as indicated by the dot-dash line 24 to an adjusting knob 25.

The contact arm 19 is also connected in series with another resistor 26 and thence to the adjustable contact arm 27 of a rheostat 28. The contact arm 27 is connected, as indicated by the dot-dash line 29, to an adjusting knob 30. Likewise the adjusting arm 23 is connected to a rheostat 31 whose contact arm 32 is connected, as indicated by the dot-dash line 33, to an adjusting knob 34.

The contact arm 32 is also connected in series with a resistor 3S and thence to a normally open contact 36 of a single pole double throw switch. The switch arm 37 is connected, as indicated by the dot-dash line 38, to the knob 39. The switch arm 37 is also connected to the switch arm 40 of a single pole double throw switch. The stationary contacts 41, 42 of this latter switch are connected through respective condensers 43, 44 to the terminal 17. The switch `arm 40 is mechanically connected, as indicated by the dot-dash line 45, to the knob 46. This switch arm 40 is also directly connected to the ter- -minal 16.

The actual voltage that is applied from the terminals 16, 17 to the device 11 will therefore be a function of the positioning of the various arms 19, 23, 32 and 27 as Well as by the capacitors 43, 44. In the off position of switch arm 37 where it engages contact 47, there is applied to the terminal 16 through the potentiometer resistor 28 a voltage determined by the setting of the arm 19 under control of knob 21. On the other hand, when the switch arm 37 is in the on position engaging contact 36, there is applied to terminal 16 a voltage determined by the setting of the arms 23 and 32. The knob 21 therefore controls the minimum voltage that is applied to the dimmer circuit 11 when the switch 37 is in its off position. On the other hand, the knob 25, by its setting, determines the maximum voltage which is applied to the dimmer circuit when the switch 37 is in its on position.

The capacitors 43, 44 in conjunction with the setting of the arms 27 and 32 determine respectively the duration of the voltage as it is increasing from its minimum to its maximum; or the duration of the voltage as it is decreasing from its maximum to its minimum. In other words, when the lamps are switched on by closing switch arm 37 on contact 36, by adjusting knob 34 the duration of the increase of illumination from minimum to maximum can be controlled by potentiometer arm 32. On the other hand, when the switch arm 37 is in the off position, the duration of the decay is controlled by the setting of knob 30 through potentiometer arm 27. The capacitor 43may be a relatively small capacitor which charges up to its maximum value, for example 50 volts DC, within a rather short period, for example, one second, this time duration being also a function of the setting of the arm 32. On the other hand, the capacitor 44 may be a relatively large capacitor which requires a much longer time to reach its full charge voltage, for example 50 volts DC.

From the foregoing it will be seen that the minimum and maximum voltages applied to terminals 16 and 17 can be independently controlled and their rate of rise and fall can also be independently controlled. Thus, as shown in FIG. 2, the full line graph 48 has a relatively fast rise from its minimum to its maximum before the lamps 12 reach their maximum brightness during the on position, while during the off position the decay of brightness is relatively slow, but even in the off position the minimum voltage can be above zero depending upon the setting of knob 21. The dotted line graph in FIG. 2 shows a typical but different arrangement of the rise and decay of the voltage for different settings of the various knobs.

FIG. 3 shows a similar series of graphs for different rise and decay times for the on and off conditions. In contrast to the graphs of FIG. 2, FIG. 3 illustrates two cases of slower rates of rise from minimum to maximum before lamps 12 reach their maximum brightness, during the on position of switch arm 37; and, in the off position of arm 37, the gure illustrates fairly rapid decays to minimal values of voltage which may be caused to occur by the equipment within unit 13 of FIG. 1. The minima of FIG. 2 are somewhat lower than those of FIG. 3 and result in lesser illumination in lamps 12.

The manner of operation of the system of FIG. 1 is along the following lines. Let it be assumed that the lamps 12 are to reach their maximum brightness rather rapidly and are to decrease their illumination at a slower rate, as indicated, for example, by the graph 48 of FIG. 2. Under that condition, the main power switch is closed to supply the 110 volt alternating current to the input of the regulator power supply 10 which applies a stabilized direct current voltage of for example volts DC to the positive terminal 14 and the negative terminal 15. This volts is then applied from potentiometer arm 23 and resistor 35 and through the switch 37 in its on position and thence to either capacitor 43 or 44. Let it be assumed that the rise in illumination is to be rather rapid, as indicated by the graph 48, in which case switch arm 40 is adjusted by knob 46 to engage contact 41. Depending upon the value of the resistors 31 and 35, this voltage builds up on the capacitor 43 at a rate determined by the setting of potentiometer arm 32. It will be understood, of course, that the switch 37, instead of being operated directly manually, may take the form of a relay which can be controlled remotely. As the DC voltage on the capacitor 43 builds up, it is applied to the dimmer circuit 11 and therefore the output voltage from dimmer 11 applied to lamps 12 goes from no voltage to full voltage depending on the growth rate of the voltage across capacitor 43.

Similarly, when switch 37 is` turned off, the capacitor 43 discharges :through the `arm 27 of the resistor 28 and the voltage across capacitor 43 decreases and the control voltage applied to dimmer 11 will also decrease until the voltage on capacitor 43 has completely disappeared. Thus it is possible to have the controlling voltage applied to the dimmer 11 come on at a fvery denite rate. It can go from off to full on for example, in five seconds depending upon the setting of poteniometer arm 32. Or it can come on from full off to full on in any range, for example of one second to twenty seconds depending upon the setting of arm 32 `and which one of the capacitors 43 or 44 is selected. The smaller the capacitor the faster the rate of growth with a given resistance. The larger the capacitor the slower the rate of growth for the same setting of arm 32. The same holds true insofar as the rate of -the decay voltage is concerned, that is, the rate of decay is faster for the smaller capaci tor and a certain setting of arm 32, as compared with the larger capacitor with that same setting.

By setting potentiometer arm 19 it is possible to choose the minimum voltage that the chosen capacitor will discharge to, and, therefore, the minimum brightness of the lamps 12 or other power device can be set. Similarly, by adjusting the potentiometer 23, the upper limit of the voltage can be set so that when the switch or relay 37 is in the on position, the light from lamps 12 will go from a certain minimum brightness to a certain maximum brightness. However, yhere again the rate is controlled by the settings of potentiometers 32 and 27 as hereinabove described.

This eiect can be duplicated with precision because of the combination of the highly stabilized and regulated power supply in conjunction with the various controls which can be calibrated if desired, in terms of brightness, time on, time off, and minimum and maximum, by means of suitable calibrated scales (not shown) adjacent each of the respective knobs. Thus, an exhibit designer can design a lighting sequence fouan exhibit or scene which will have a certain minimum brightness, a certain maximum brightness, will go from minimum brightness to maximum brightness in a predetermined interval, and from maximum brightness to minimum brightness during another interval which can be different from the on cycle.

It will be clear from the foregoing that unit 13 hereinabove described may be used in conjunction with any system where a power device is to be controlled and the dimmer circuit 11 is merely representative of any similar device. Since the voltages at the terminals `16 and 17 are control voltages, the device 11 should be of any known type which produces output power in proportion to the said voltages and their characteristic curves relating voltage to time. Typical of such a device is the dimmer circuit made by Century Lighting Inc. and known as Century Type CCR Dimmer, Model 406.

In one particular arrangement that was found to produce satisfactory results, the supply 10' was of a type which produced at the terminals 14 and 15 a highly stabilized voltage of approximately 100 volts DC. Each of the potentiometers 18 and 22 was a 5,000 ohm 5 watt resistor. The potentiometers 31 and 28 each was a 15,000 ohm 5 watt. Each of the resistors 26 and 35 was 100 ohm 5 watt. The capacitor 43 had a capacitance of 500 mfds.; and capacitor 44 was 2,000 mfds.

While one particular embodiment of the invention has been described, it will be understood that 'various changes and modifications may be made therein without departing from its scope.

What is claimed is:

1. A voltage generator for varying the electrical power fed by a light intensity controller to an illumination device comprising:

a source of DC voltage of substantially constant amplitude,

means responsive to the DC voltage source for producing a irst control voltage indicative of a preselected maximum intensity level of the illumination device,

means responsive to the DC voltage source for producing a second control voltage indicative of a preselected minimum intensity level of the illumination device,

a charging circuit comprising a iirst variable resistor and a capacitor coupled lacross the input to the light intensity controller, said lirst variable resistor coupling said irst control voltage -to charge said capacitor at a rate selected by said rst variable resistor,

a discharge circuit including a second variable resistor coupling the second control voltage to discharge said capacitor towards the second control voltage level at a rate 4selected by said second variable resistor,

and first switch means for alternatively coupling said iirst and second ivariable resistors to said capacitor to increase the power to the illumination device to a level determined by the rst control voltage and at a rate selected by said lirst variable resistor and decrease the power to the illumination device to a level controlled by said .-second control voltage and at a rate selected by said second variable resistor.

2. The device as recited in claim 1 wherein said first control voltage-producing means further comprises,

a first potentiometer coupling said DC voltage source to said first switch means to vary the maximum intensity level voltage supplied to the light intensity controller and,

wherein said second voltage-producing means includes a second potentiometer coupling said DC voltage source to the switch means to var-y the minimum intensity control signal to the light intensity controller.

References Cited f UNITED STATES PATENTS 2,366,415 1/1945 Lindsay 323--64 X 2,958,027 10/ 1960 Moseley et al 320-1 X FOREIGN PATENTS 613,766 1/1961 Canada.

OTHER REFERENCES Bitetto and Stamm: Waveform Shaping Circuit TBM Technical Disclosure Bulletin, vol. 2, No. 4, December 1959 p. 88.

JOHN F. COUCH, Primary Examiner.

A. D. PELLINEN, Assistant Examiner.v

U.S. Cl. X.R. 

